1. Field of the Invention
The present invention relates to printers, and, more particularly, to apparatus and method for varying a spacing between at least two printing elements, such as ink jet nozzles, in a printing system.
2. Description of the Related Art
An ink jet printer typically includes a printhead having an array of ink emitting orifices, or nozzles, formed therein. The printhead is mounted on a carriage assembly which scans a width of the print medium. During a scan of the carriage assembly, ink is jetted from selected ones of the ink emitting orifices to produce a desired print image on the print medium.
It is also known to provide an ink jet printer with a printhead which extends substantially across the width of the print medium. For an ink jet printer with a 300 dot per inch (dpi) resolution, a single row of ink emitting orifices in such a printhead would include at least 2400 ink emitting orifices (i.e., 300 orifices/inch * 8 inches/page width=2400 orifices/page width).
With a page wide printhead as described above, a print quality problem may arise with respect to the associated physical geometry of the printhead due to the spatial locality of the ink emitting orifices. Because the orifices are located in a substantially linear array extending across the width of the print medium, ink dots from adjacent orifices which are to be placed within a given raster are placed on the print medium at approximately the same time. If the printhead includes multiple rows of orifices extending across the width of the page, adjacent ink dots in a given row and adjacent ink dots between rows are placed on the print medium in close proximity to each other with respect to time. For various print media, particularly transparencies, poor print quality results when ink dots are placed at adjacent positions on the print medium at approximately the same time.